首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   20341篇
  免费   1319篇
  国内免费   80篇
耳鼻咽喉   175篇
儿科学   459篇
妇产科学   461篇
基础医学   2949篇
口腔科学   763篇
临床医学   2310篇
内科学   4266篇
皮肤病学   432篇
神经病学   1828篇
特种医学   547篇
外科学   2246篇
综合类   122篇
一般理论   9篇
预防医学   1914篇
眼科学   271篇
药学   1598篇
中国医学   106篇
肿瘤学   1284篇
  2023年   178篇
  2022年   198篇
  2021年   526篇
  2020年   328篇
  2019年   562篇
  2018年   750篇
  2017年   538篇
  2016年   580篇
  2015年   743篇
  2014年   825篇
  2013年   1127篇
  2012年   1719篇
  2011年   1740篇
  2010年   822篇
  2009年   694篇
  2008年   1259篇
  2007年   1279篇
  2006年   1207篇
  2005年   1131篇
  2004年   1091篇
  2003年   993篇
  2002年   932篇
  2001年   224篇
  2000年   183篇
  1999年   174篇
  1998年   117篇
  1997年   96篇
  1996年   109篇
  1995年   72篇
  1994年   55篇
  1993年   51篇
  1992年   112篇
  1991年   77篇
  1990年   106篇
  1989年   85篇
  1988年   77篇
  1987年   94篇
  1986年   113篇
  1985年   87篇
  1984年   81篇
  1983年   63篇
  1982年   49篇
  1981年   52篇
  1980年   34篇
  1979年   44篇
  1977年   26篇
  1976年   25篇
  1975年   25篇
  1974年   28篇
  1971年   29篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
11.
12.
13.
14.
15.
The aim of this study was to investigate retrospectively the efficacy of expandable metallic stents (EMSs) for severe respiratory distress in patients with central airway obstruction. Twenty patients with central airway obstructions were treated with an EMS. An intraluminal stricture was present in 15 and an extraluminal stricture in 5 patients. Of the 15 patients with intraluminal stenosis, 11 exhibited symptomatic improvement. All 11 patients had tumor infiltration occupying less than 50% of the endoluminal diameter. The other four patients with intraluminal stenosis had tumor infiltration occupying > 50% of the endoluminal diameter and demonstrated no improvement. All five patients with extraluminal stenosis were improved. EMS is useful for an extraluminal stricture in the central airway and the effect of EMS for intraluminal stenosis is related to the degree of infiltration and of tumor progression itself.   相似文献   
16.
Recent reports suggest that oxygen radical-induced lipid peroxidation plays a role in the retrograde degeneration of motor neurons following facial nerve axotomy in the neonatal rat. The purpose of the present study was to explore this notion further by testing the neuroprotective properties of two novel brain-penetrating, lipid peroxidation inhibitors, U-101033E and U-104067F, in this model of neuronal degeneration. In Experiment 1, 14-day-old rats were pretreated with 3, 10, or 30 mg/kg U-101033E (po) 10 min before right facial nerve axotomy (Day 0) and then posttreated once a day from Day 1 to Day 6, and once every other day from Day 8 to Day 21. Rats were sacrificed 21 days postaxotomy and surviving cholinergic cell bodies were identified using choline acetyltransferase immunocytochemistry. Both 10 and 30 mg/kg U-101033E significantly enhanced motor neuron survival, with survival rates of 65.9–88.9% being noted in comparison to 51.7–62% survival in vehicle controls (P ≤ 0.05). Experiment 2 demonstrated a significant neuroprotective effect of 10 and 30 mg/kg U-104067F using the same dosing schedule. Experiment 3 was designed to test whether shorter periods of drug exposure (e.g., 5 or 7 days) would be sufficient to preserve motor neurons in rats treated with 10 mg/kg U-101033E. The results suggested that as little as 5 days of drug treatment is sufficient to enhance motor neuron survival. Finally, Experiment 4 demonstrated an 18–19% increase in motor neuron survival in rats treated with 10 and 30 mg/kg U-104067F for 5 consecutive days postaxotomy. Taken together, the attenuation of motor neuron degeneration by the two pyrrolopyrimidine lipid peroxidation inhibitors, U-101033E and U-104067F, lends support to the notion that lipid peroxidation contributes to the pathogenesis of axotomy-induced neurodegeneration.  相似文献   
17.
Aims: On the Edge is a mental health education programme designed to support early intervention by increasing knowledge and understanding of early psychosis, reducing the stigma associated with mental health issues and improving awareness of avenues of help. The target audience was young people aged 14–22 years in schools and colleges. Methods: An interactive drama programme was developed through collaborative working across psychiatry, applied drama and those with direct experience of psychosis. A national tour engaged 2500 students in 71 performances that took place in 51 schools and colleges. The programme was evaluated against its aims with data collected both during and after the tour. Results: Quantitative and qualitative evaluation found significant gains with respect to all three aims. Thirty‐one schools developed supportive links with local mental health services. Conclusions: This programme shows the value and effectiveness of delivering health education on early psychosis through the medium of applied drama, and offers a model for a programme that can be incorporated into early intervention services. Lessons learned through delivering this programme are a valuable contribution towards future developments of mental health education programmes for schools.  相似文献   
18.

Introduction  

This paper presents the results of a study on the psychometric properties of an authorized Spanish version of the McMaster Family Assessment Device, a self-report measure of family functioning.  相似文献   
19.
20.
A model is described for obtaining long-term and stable discriminative conditioning-related slow-potential and single-unit responses from the frontal cortex of urethane-anesthetized rats. Responses were recorded and analyzed to reinforced (rewarding medial forebrain bundle stimulation) and non-reinforced tone cues. In the present study, cortical event-related slow potentials provided an adequate index of the level of discriminative conditioning. Single-unit response patterns are described for 57 neurons which demonstrated a discriminative response to either the reinforced or non-reinforced tone cue.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号